src/termhooks.h

   1 /* Parameters and display hooks for terminal devices.
   2
   3 Copyright (C) 1985-1986, 1993-1994, 2001-2013 Free Software Foundation,
   4 Inc.
   5
   6 This file is part of GNU Emacs.
   7
   8 GNU Emacs is free software: you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation, either version 3 of the License, or
  11 (at your option) any later version.
  12
  13 GNU Emacs is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef EMACS_TERMHOOKS_H
  22 #define EMACS_TERMHOOKS_H
  23
  24 /* Miscellanea.   */
  25
  26 #include "systime.h" /* for Time */
  27
  28 INLINE_HEADER_BEGIN
  29 #ifndef TERMHOOKS_INLINE
  30 # define TERMHOOKS_INLINE INLINE
  31 #endif
  32
  33 enum scroll_bar_part {
  34   scroll_bar_above_handle,
  35   scroll_bar_handle,
  36   scroll_bar_below_handle,
  37   scroll_bar_up_arrow,
  38   scroll_bar_down_arrow,
  39   scroll_bar_to_top,
  40   scroll_bar_to_bottom,
  41   scroll_bar_end_scroll,
  42   scroll_bar_move_ratio
  43 };
  44
  45 /* If the value of the frame parameter changed, whis hook is called.
  46    For example, if going from fullscreen to not fullscreen this hook
  47    may do something OS dependent, like extended window manager hints on X11.  */
  48 extern void (*fullscreen_hook) (struct frame *f);
  49
  50 /* Output method of a terminal (and frames on this terminal, respectively).  */
  51
  52 enum output_method
  53 {
  54   output_initial,
  55   output_termcap,
  56   output_x_window,
  57   output_msdos_raw,
  58   output_w32,
  59   output_ns
  60 };
  61
  62 /* Input queue declarations and hooks.  */
  63
  64 enum event_kind
  65 {
  66   NO_EVENT,                     /* nothing happened.  This should never
  67                                    actually appear in the event queue.  */
  68
  69   ASCII_KEYSTROKE_EVENT,        /* The ASCII code is in .code, perhaps
  70                                    with modifiers applied.
  71                                    .modifiers holds the state of the
  72                                    modifier keys.
  73                                    .frame_or_window is the frame in
  74                                    which the key was typed.
  75                                    .timestamp gives a timestamp (in
  76                                    milliseconds) for the keystroke.  */
  77   MULTIBYTE_CHAR_KEYSTROKE_EVENT,       /* The multibyte char code is in .code,
  78                                    perhaps with modifiers applied.
  79                                    The others are the same as
  80                                    ASCII_KEYSTROKE_EVENT.  */
  81   NON_ASCII_KEYSTROKE_EVENT,    /* .code is a number identifying the
  82                                    function key.  A code N represents
  83                                    a key whose name is
  84                                    function_key_names[N]; function_key_names
  85                                    is a table in keyboard.c to which you
  86                                    should feel free to add missing keys.
  87                                    .modifiers holds the state of the
  88                                    modifier keys.
  89                                    .frame_or_window is the frame in
  90                                    which the key was typed.
  91                                    .timestamp gives a timestamp (in
  92                                    milliseconds) for the keystroke.  */
  93   TIMER_EVENT,                  /* A timer fired.  */
  94   MOUSE_CLICK_EVENT,            /* The button number is in .code; it must
  95                                    be >= 0 and < NUM_MOUSE_BUTTONS, defined
  96                                    below.
  97                                    .modifiers holds the state of the
  98                                    modifier keys.
  99                                    .x and .y give the mouse position,
 100                                    in characters, within the window.
 101                                    .frame_or_window gives the frame
 102                                    the mouse click occurred in.
 103                                    .timestamp gives a timestamp (in
 104                                    milliseconds) for the click.  */
 105   WHEEL_EVENT,                  /* A wheel event is generated by a
 106                                    wheel on a mouse (e.g., MS
 107                                    Intellimouse).
 108                                    .modifiers holds the rotate
 109                                    direction (up or down), and the
 110                                    state of the modifier keys.
 111                                    .x and .y give the mouse position,
 112                                    in characters, within the window.
 113                                    .frame_or_window gives the frame
 114                                    the wheel event occurred in.
 115                                    .timestamp gives a timestamp (in
 116                                    milliseconds) for the event.  */
 117   HORIZ_WHEEL_EVENT,            /* A wheel event generated by a second
 118                                    horizontal wheel that is present on some
 119                                    mice. See WHEEL_EVENT.  */
 120 #ifdef HAVE_NTGUI
 121   LANGUAGE_CHANGE_EVENT,        /* A LANGUAGE_CHANGE_EVENT is
 122                                    generated when HAVE_NTGUI or on Mac OS
 123                                    when the keyboard layout or input
 124                                    language is changed by the
 125                                    user.  */
 126 #endif
 127   SCROLL_BAR_CLICK_EVENT,       /* .code gives the number of the mouse button
 128                                    that was clicked.
 129                                    .modifiers holds the state of the modifier
 130                                    keys.
 131                                    .part is a lisp symbol indicating which
 132                                    part of the scroll bar got clicked.
 133                                    .x gives the distance from the start of the
 134                                    scroll bar of the click; .y gives the total
 135                                    length of the scroll bar.
 136                                    .frame_or_window gives the window
 137                                    whose scroll bar was clicked in.
 138                                    .timestamp gives a timestamp (in
 139                                    milliseconds) for the click.  */
 140   SELECTION_REQUEST_EVENT,      /* Another X client wants a selection from us.
 141                                    See `struct selection_input_event'.  */
 142   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
 143   BUFFER_SWITCH_EVENT,          /* A process filter has switched buffers.  */
 144   DELETE_WINDOW_EVENT,          /* An X client said "delete this window".  */
 145   MENU_BAR_EVENT,               /* An event generated by the menu bar.
 146                                    The frame_or_window field's cdr holds the
 147                                    Lisp-level event value.
 148                                    (Only the toolkit version uses these.)  */
 149   ICONIFY_EVENT,                /* An X client iconified this window.  */
 150   DEICONIFY_EVENT,              /* An X client deiconified this window.  */
 151   MENU_BAR_ACTIVATE_EVENT,      /* A button press in the menu bar
 152                                    (toolkit version only).  */
 153   DRAG_N_DROP_EVENT,            /* A drag-n-drop event is generated when
 154                                    files selected outside of Emacs are dropped
 155                                    onto an Emacs window.
 156                                    .modifiers holds the state of the
 157                                    modifier keys.
 158                                    .x and .y give the mouse position,
 159                                    in characters, within the window.
 160                                    .frame_or_window is the frame in
 161                                    which the drop was made.
 162                                    .arg is a platform-dependent
 163                                    representation of the dropped items.
 164                                    .timestamp gives a timestamp (in
 165                                    milliseconds) for the click.  */
 166   USER_SIGNAL_EVENT,            /* A user signal.
 167                                    code is a number identifying it,
 168                                    index into lispy_user_signals.  */
 169
 170   /* Help events.  Member `frame_or_window' of the input_event is the
 171      frame on which the event occurred, and member `arg' contains
 172      the help to show.  */
 173   HELP_EVENT,
 174
 175   /* An event from a tool-bar.  Member `arg' of the input event
 176      contains the tool-bar item selected.  If `frame_or_window'
 177      and `arg' are equal, this is a prefix event.  */
 178   TOOL_BAR_EVENT,
 179
 180   /* Queued from XTread_socket on FocusIn events.  Translated into
 181      `switch-frame' events in kbd_buffer_get_event, if necessary.  */
 182   FOCUS_IN_EVENT,
 183
 184   FOCUS_OUT_EVENT,
 185
 186   /* Generated when mouse moves over window not currently selected.  */
 187   SELECT_WINDOW_EVENT,
 188
 189   /* Queued from XTread_socket when session manager sends
 190      save yourself before shutdown. */
 191   SAVE_SESSION_EVENT
 192
 193 #ifdef HAVE_GPM
 194   , GPM_CLICK_EVENT
 195 #endif
 196
 197 #ifdef HAVE_DBUS
 198   , DBUS_EVENT
 199 #endif
 200
 201   , CONFIG_CHANGED_EVENT
 202
 203 #ifdef HAVE_NTGUI
 204   /* Generated when an APPCOMMAND event is received, in response to
 205      Multimedia or Internet buttons on some keyboards.
 206      Such keys are available as normal function keys on X through the
 207      Xkeyboard extension.
 208      On Windows, some of them get mapped to normal function key events,
 209      but others need to be handled by APPCOMMAND. Handling them all as
 210      APPCOMMAND events means they can be disabled
 211      (w32-pass-multimedia-buttons-to-system), important on Windows since
 212      the system never sees these keys if Emacs claims to handle them.
 213      On X, the window manager seems to grab the keys it wants
 214      first, so this is not a problem there.  */
 215   , MULTIMEDIA_KEY_EVENT
 216 #endif
 217
 218 #ifdef HAVE_NS
 219   /* Generated when native multi-keystroke input method is used to modify
 220      tentative or indicative text display. */
 221   , NS_TEXT_EVENT
 222   /* Non-key system events (e.g. application menu events) */
 223   , NS_NONKEY_EVENT
 224 #endif
 225
 226 #ifdef USE_FILE_NOTIFY
 227   /* File or directory was changed.  */
 228   , FILE_NOTIFY_EVENT
 229 #endif
 230
 231 };
 232
 233 /* If a struct input_event has a kind which is SELECTION_REQUEST_EVENT
 234    or SELECTION_CLEAR_EVENT, then its contents are really described
 235    by `struct selection_input_event'; see xterm.h.  */
 236
 237 /* The keyboard input buffer is an array of these structures.  Each one
 238    represents some sort of input event - a keystroke, a mouse click, or
 239    a window system event.  These get turned into their lispy forms when
 240    they are removed from the event queue.  */
 241
 242 struct input_event
 243 {
 244   /* What kind of event was this?  */
 245   enum event_kind kind;
 246
 247   /* For an ASCII_KEYSTROKE_EVENT and MULTIBYTE_CHAR_KEYSTROKE_EVENT,
 248      this is the character.
 249      For a NON_ASCII_KEYSTROKE_EVENT, this is the keysym code.
 250      For a mouse event, this is the button number.
 251      For a HELP_EVENT, this is the position within the object
 252       (stored in ARG below) where the help was found.  */
 253   /* In WindowsNT, for a mouse wheel event, this is the delta.  */
 254   ptrdiff_t code;
 255   enum scroll_bar_part part;
 256
 257   int modifiers;                /* See enum below for interpretation.  */
 258
 259   Lisp_Object x, y;
 260   Time timestamp;
 261
 262   /* This field is copied into a vector while the event is in
 263      the queue, so that garbage collections won't kill it.  */
 264   Lisp_Object frame_or_window;
 265
 266   /* Additional event argument.  This is used for TOOL_BAR_EVENTs and
 267      HELP_EVENTs and avoids calling Fcons during signal handling.  */
 268   Lisp_Object arg;
 269 };
 270
 271 #define EVENT_INIT(event) memset (&(event), 0, sizeof (struct input_event))
 272
 273 /* Bits in the modifiers member of the input_event structure.
 274    Note that reorder_modifiers assumes that the bits are in canonical
 275    order.
 276
 277    The modifiers applied to mouse clicks are rather ornate.  The
 278    window-system-specific code should store mouse clicks with
 279    up_modifier or down_modifier set.  Having an explicit down modifier
 280    simplifies some of window-system-independent code; without it, the
 281    code would have to recognize down events by checking if the event
 282    is a mouse click lacking the click and drag modifiers.
 283
 284    The window-system independent code turns all up_modifier events
 285    bits into drag_modifier, click_modifier, double_modifier, or
 286    triple_modifier events.  The click_modifier has no written
 287    representation in the names of the symbols used as event heads,
 288    but it does appear in the Qevent_symbol_components property of the
 289    event heads.  */
 290 enum {
 291   up_modifier   =   1,          /* Only used on mouse buttons - always
 292                                    turned into a click or a drag modifier
 293                                    before lisp code sees the event.  */
 294   down_modifier =   2,          /* Only used on mouse buttons.  */
 295   drag_modifier =   4,          /* This is never used in the event
 296                                    queue; it's only used internally by
 297                                    the window-system-independent code.  */
 298   click_modifier=   8,          /* See drag_modifier.  */
 299   double_modifier= 16,          /* See drag_modifier.  */
 300   triple_modifier= 32,          /* See drag_modifier.  */
 301
 302   /* The next four modifier bits are used also in keyboard events at
 303      the Lisp level.
 304
 305      It's probably not the greatest idea to use the 2^28 bit for any
 306      modifier.  It may or may not be the sign bit, depending on
 307      FIXNUM_BITS, so using it to represent a modifier key means that
 308      characters thus modified have different integer equivalents
 309      depending on the architecture they're running on.  Oh, and
 310      applying XINT to a character whose 2^28 bit is set might sign-extend
 311      it, so you get a bunch of bits in the mask you didn't want.
 312
 313      The CHAR_ macros are defined in lisp.h.  */
 314   alt_modifier  =  CHAR_ALT,    /* Under X, the XK_Alt_[LR] keysyms.  */
 315   super_modifier=  CHAR_SUPER,  /* Under X, the XK_Super_[LR] keysyms.  */
 316   hyper_modifier=  CHAR_HYPER,  /* Under X, the XK_Hyper_[LR] keysyms.  */
 317   shift_modifier=  CHAR_SHIFT,
 318   ctrl_modifier =  CHAR_CTL,
 319   meta_modifier =  CHAR_META    /* Under X, the XK_Meta_[LR] keysyms.  */
 320 };
 321
 322 #ifdef HAVE_GPM
 323 #include <gpm.h>
 324 extern int handle_one_term_event (struct tty_display_info *, Gpm_Event *, struct input_event *);
 325 #ifndef HAVE_WINDOW_SYSTEM
 326 extern void term_mouse_moveto (int, int);
 327 #endif
 328
 329 /* The device for which we have enabled gpm support.  */
 330 extern struct tty_display_info *gpm_tty;
 331 #endif
 332
 333 /* Terminal-local parameters. */
 334 struct terminal
 335 {
 336   /* This is for Lisp; the terminal code does not refer to it.  */
 337   struct vectorlike_header header;
 338
 339   /* Parameter alist of this terminal.  */
 340   Lisp_Object param_alist;
 341
 342   /* List of charsets supported by the terminal.  It is set by
 343      Fset_terminal_coding_system_internal along with
 344      the member terminal_coding.  */
 345   Lisp_Object charset_list;
 346
 347   /* This is an association list containing the X selections that
 348      Emacs might own on this terminal.  Each element has the form
 349        (SELECTION-NAME SELECTION-VALUE SELECTION-TIMESTAMP FRAME)
 350      SELECTION-NAME is a lisp symbol, whose name is the name of an X Atom.
 351      SELECTION-VALUE is the value that emacs owns for that selection.
 352       It may be any kind of Lisp object.
 353      SELECTION-TIMESTAMP is the time at which emacs began owning this
 354       selection, as a cons of two 16-bit numbers (making a 32 bit
 355       time.)
 356      FRAME is the frame for which we made the selection.  If there is
 357       an entry in this alist, then it can be assumed that Emacs owns
 358       that selection.
 359      The only (eq) parts of this list that are visible from Lisp are
 360     the selection-values.  */
 361   Lisp_Object Vselection_alist;
 362
 363   /* All fields before `next_terminal' should be Lisp_Object and are traced
 364      by the GC.  All fields afterwards are ignored by the GC.  */
 365
 366   /* Chain of all terminal devices. */
 367   struct terminal *next_terminal;
 368
 369   /* Unique id for this terminal device. */
 370   int id;
 371
 372   /* The number of frames that are on this terminal. */
 373   int reference_count;
 374
 375   /* The type of the terminal device. */
 376   enum output_method type;
 377
 378   /* The name of the terminal device.  Do not use this to uniquely
 379      identify a terminal; the same device may be opened multiple
 380      times. */
 381   char *name;
 382
 383   /* The terminal's keyboard object. */
 384   struct kboard *kboard;
 385
 386 #ifdef HAVE_WINDOW_SYSTEM
 387   /* Cache of images.  */
 388   struct image_cache *image_cache;
 389 #endif /* HAVE_WINDOW_SYSTEM */
 390
 391   /* Device-type dependent data shared amongst all frames on this terminal.  */
 392   union display_info
 393   {
 394     struct tty_display_info *tty;     /* termchar.h */
 395     struct x_display_info *x;         /* xterm.h */
 396     struct w32_display_info *w32;     /* w32term.h */
 397     struct ns_display_info *ns;       /* nsterm.h */
 398   } display_info;
 399
 400 \f
 401   /* Coding-system to be used for encoding terminal output.  This
 402      structure contains information of a coding-system specified by
 403      the function `set-terminal-coding-system'.  Also see
 404      `safe_terminal_coding' in coding.h.  */
 405   struct coding_system *terminal_coding;
 406
 407   /* Coding-system of what is sent from terminal keyboard.  This
 408      structure contains information of a coding-system specified by
 409      the function `set-keyboard-coding-system'.  */
 410   struct coding_system *keyboard_coding;
 411
 412   /* Terminal characteristics.  */
 413   /* XXX Are these really used on non-termcap displays?  */
 414
 415   int must_write_spaces;        /* Nonzero means spaces in the text must
 416                                    actually be output; can't just skip over
 417                                    some columns to leave them blank.  */
 418   int fast_clear_end_of_line;   /* Nonzero means terminal has a `ce' string.  */
 419
 420   int line_ins_del_ok;          /* Terminal can insert and delete lines.  */
 421   int char_ins_del_ok;          /* Terminal can insert and delete chars.  */
 422   int scroll_region_ok;         /* Terminal supports setting the scroll
 423                                    window.  */
 424   int scroll_region_cost;       /* Cost of setting the scroll window,
 425                                    measured in characters.  */
 426   int memory_below_frame;       /* Terminal remembers lines scrolled
 427                                    off bottom.  */
 428
 429   /* Window-based redisplay interface for this device (0 for tty
 430      devices). */
 431   struct redisplay_interface *rif;
 432
 433   /* Frame-based redisplay interface. */
 434
 435   /* Text display hooks.  */
 436
 437   void (*cursor_to_hook) (struct frame *f, int vpos, int hpos);
 438   void (*raw_cursor_to_hook) (struct frame *, int, int);
 439
 440   void (*clear_to_end_hook) (struct frame *);
 441   void (*clear_frame_hook) (struct frame *);
 442   void (*clear_end_of_line_hook) (struct frame *, int);
 443
 444   void (*ins_del_lines_hook) (struct frame *f, int, int);
 445
 446   void (*insert_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 447   void (*write_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 448   void (*delete_glyphs_hook) (struct frame *, int);
 449
 450   void (*ring_bell_hook) (struct frame *f);
 451   void (*toggle_invisible_pointer_hook) (struct frame *f, int invisible);
 452
 453   void (*reset_terminal_modes_hook) (struct terminal *);
 454   void (*set_terminal_modes_hook) (struct terminal *);
 455
 456   void (*update_begin_hook) (struct frame *);
 457   void (*update_end_hook) (struct frame *);
 458   void (*set_terminal_window_hook) (struct frame *, int);
 459
 460   /* Multi-frame and mouse support hooks.  */
 461
 462   /* Return the current position of the mouse.
 463
 464      Set *f to the frame the mouse is in, or zero if the mouse is in no
 465      Emacs frame.  If it is set to zero, all the other arguments are
 466      garbage.
 467
 468      If the motion started in a scroll bar, set *bar_window to the
 469      scroll bar's window, *part to the part the mouse is currently over,
 470      *x to the position of the mouse along the scroll bar, and *y to the
 471      overall length of the scroll bar.
 472
 473      Otherwise, set *bar_window to Qnil, and *x and *y to the column and
 474      row of the character cell the mouse is over.
 475
 476      Set *time to the time the mouse was at the returned position.  */
 477   void (*mouse_position_hook) (struct frame **f, int,
 478                                Lisp_Object *bar_window,
 479                                enum scroll_bar_part *part,
 480                                Lisp_Object *x,
 481                                Lisp_Object *y,
 482                                Time *);
 483
 484   /* When a frame's focus redirection is changed, this hook tells the
 485      window system code to re-decide where to put the highlight.  Under
 486      X, this means that Emacs lies about where the focus is.  */
 487   void (*frame_rehighlight_hook) (struct frame *);
 488
 489   /* If we're displaying frames using a window system that can stack
 490      frames on top of each other, this hook allows you to bring a frame
 491      to the front, or bury it behind all the other windows.  If this
 492      hook is zero, that means the terminal we're displaying on doesn't
 493      support overlapping frames, so there's no need to raise or lower
 494      anything.
 495
 496      If RAISE_FLAG is non-zero, F is brought to the front, before all other
 497      windows.  If RAISE_FLAG is zero, F is sent to the back, behind all other
 498      windows.  */
 499   void (*frame_raise_lower_hook) (struct frame *f, int raise_flag);
 500
 501   /* If the value of the frame parameter changed, whis hook is called.
 502      For example, if going from fullscreen to not fullscreen this hook
 503      may do something OS dependent, like extended window manager hints on X11.  */
 504   void (*fullscreen_hook) (struct frame *f);
 505
 506   \f
 507   /* Scroll bar hooks.  */
 508
 509   /* The representation of scroll bars is determined by the code which
 510      implements them, except for one thing: they must be represented by
 511      lisp objects.  This allows us to place references to them in
 512      Lisp_Windows without worrying about those references becoming
 513      dangling references when the scroll bar is destroyed.
 514
 515      The window-system-independent portion of Emacs just refers to
 516      scroll bars via their windows, and never looks inside the scroll bar
 517      representation; it always uses hook functions to do all the
 518      scroll bar manipulation it needs.
 519
 520      The `vertical_scroll_bar' field of a Lisp_Window refers to that
 521      window's scroll bar, or is nil if the window doesn't have a
 522      scroll bar.
 523
 524      The `scroll_bars' and `condemned_scroll_bars' fields of a Lisp_Frame
 525      are free for use by the scroll bar implementation in any way it sees
 526      fit.  They are marked by the garbage collector.  */
 527
 528
 529   /* Set the vertical scroll bar for WINDOW to have its upper left corner
 530      at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 531      indicate that we are displaying PORTION characters out of a total
 532      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 533      have a scroll bar, create one for it.  */
 534   void (*set_vertical_scroll_bar_hook) (struct window *window,
 535                                         int portion, int whole,
 536                                         int position);
 537
 538
 539   /* The following three hooks are used when we're doing a thorough
 540      redisplay of the frame.  We don't explicitly know which scroll bars
 541      are going to be deleted, because keeping track of when windows go
 542      away is a real pain - can you say set-window-configuration?
 543      Instead, we just assert at the beginning of redisplay that *all*
 544      scroll bars are to be removed, and then save scroll bars from the
 545      fiery pit when we actually redisplay their window.  */
 546
 547   /* Arrange for all scroll bars on FRAME to be removed at the next call
 548      to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
 549      `*redeem_scroll_bar_hook' is applied to its window before the judgment.
 550
 551      This should be applied to each frame each time its window tree is
 552      redisplayed, even if it is not displaying scroll bars at the moment;
 553      if the HAS_SCROLL_BARS flag has just been turned off, only calling
 554      this and the judge_scroll_bars_hook will get rid of them.
 555
 556      If non-zero, this hook should be safe to apply to any frame,
 557      whether or not it can support scroll bars, and whether or not it is
 558      currently displaying them.  */
 559   void (*condemn_scroll_bars_hook) (struct frame *frame);
 560
 561   /* Unmark WINDOW's scroll bar for deletion in this judgment cycle.
 562      Note that it's okay to redeem a scroll bar that is not condemned.  */
 563   void (*redeem_scroll_bar_hook) (struct window *window);
 564
 565   /* Remove all scroll bars on FRAME that haven't been saved since the
 566      last call to `*condemn_scroll_bars_hook'.
 567
 568      This should be applied to each frame after each time its window
 569      tree is redisplayed, even if it is not displaying scroll bars at the
 570      moment; if the HAS_SCROLL_BARS flag has just been turned off, only
 571      calling this and condemn_scroll_bars_hook will get rid of them.
 572
 573      If non-zero, this hook should be safe to apply to any frame,
 574      whether or not it can support scroll bars, and whether or not it is
 575      currently displaying them.  */
 576   void (*judge_scroll_bars_hook) (struct frame *FRAME);
 577
 578 \f
 579   /* Called to read input events.
 580
 581      TERMINAL indicates which terminal device to read from.  Input
 582      events should be read into HOLD_QUIT.
 583
 584      A positive return value indicates that that many input events
 585      were read into BUF.
 586      Zero means no events were immediately available.
 587      A value of -1 means a transient read error, while -2 indicates
 588      that the device was closed (hangup), and it should be deleted.  */
 589   int (*read_socket_hook) (struct terminal *terminal,
 590                            struct input_event *hold_quit);
 591
 592   /* Called when a frame's display becomes entirely up to date.  */
 593   void (*frame_up_to_date_hook) (struct frame *);
 594
 595 \f
 596   /* Called to delete the device-specific portions of a frame that is
 597      on this terminal device. */
 598   void (*delete_frame_hook) (struct frame *);
 599
 600   /* Called after the last frame on this terminal is deleted, or when
 601      the display device was closed (hangup).
 602
 603      If this is NULL, then the generic delete_terminal is called
 604      instead.  Otherwise the hook must call delete_terminal itself.
 605
 606      The hook must check for and close any live frames that are still
 607      on the terminal.  delete_frame ensures that there are no live
 608      frames on the terminal when it calls this hook, so infinite
 609      recursion is prevented.  */
 610   void (*delete_terminal_hook) (struct terminal *);
 611 };
 612
 613 /* Most code should use these functions to set Lisp fields in struct
 614    terminal.  */
 615 TERMHOOKS_INLINE void
 616 tset_charset_list (struct terminal *t, Lisp_Object val)
 617 {
 618   t->charset_list = val;
 619 }
 620 TERMHOOKS_INLINE void
 621 tset_selection_alist (struct terminal *t, Lisp_Object val)
 622 {
 623   t->Vselection_alist = val;
 624 }
 625
 626 /* Chain of all terminal devices currently in use.  */
 627 extern struct terminal *terminal_list;
 628
 629 #define FRAME_MUST_WRITE_SPACES(f) ((f)->terminal->must_write_spaces)
 630 #define FRAME_FAST_CLEAR_END_OF_LINE(f) ((f)->terminal->fast_clear_end_of_line)
 631 #define FRAME_LINE_INS_DEL_OK(f) ((f)->terminal->line_ins_del_ok)
 632 #define FRAME_CHAR_INS_DEL_OK(f) ((f)->terminal->char_ins_del_ok)
 633 #define FRAME_SCROLL_REGION_OK(f) ((f)->terminal->scroll_region_ok)
 634 #define FRAME_SCROLL_REGION_COST(f) ((f)->terminal->scroll_region_cost)
 635 #define FRAME_MEMORY_BELOW_FRAME(f) ((f)->terminal->memory_below_frame)
 636
 637 #define FRAME_TERMINAL_CODING(f) ((f)->terminal->terminal_coding)
 638 #define FRAME_KEYBOARD_CODING(f) ((f)->terminal->keyboard_coding)
 639
 640 #define TERMINAL_TERMINAL_CODING(d) ((d)->terminal_coding)
 641 #define TERMINAL_KEYBOARD_CODING(d) ((d)->keyboard_coding)
 642
 643 #define FRAME_RIF(f) ((f)->terminal->rif)
 644
 645 #define FRAME_TERMINAL(f) ((f)->terminal)
 646
 647 /* Return true if the terminal device is not suspended.  */
 648 #define TERMINAL_ACTIVE_P(d)                                            \
 649   (((d)->type != output_termcap && (d)->type != output_msdos_raw)       \
 650    || (d)->display_info.tty->input)
 651
 652 extern struct terminal *get_terminal (Lisp_Object terminal, bool);
 653 extern struct terminal *create_terminal (void);
 654 extern void delete_terminal (struct terminal *);
 655
 656 /* The initial terminal device, created by initial_term_init.  */
 657 extern struct terminal *initial_terminal;
 658
 659 extern unsigned char *encode_terminal_code (struct glyph *, int,
 660                                             struct coding_system *);
 661
 662 #ifdef HAVE_GPM
 663 extern void close_gpm (int gpm_fd);
 664 #endif
 665
 666 INLINE_HEADER_END
 667
 668 #endif /* EMACS_TERMHOOKS_H */